Scale



L. T. JOHNSON.

SCALE.

APPLICATION FILED OCT-18, 191s.

Patented Deu.27, 1921.

070105020 Ma, w-

Zach/m 3 L Nl'l'ED STATES LEONARD T. JOHNSON, OF BOSTON, MASSACI-I'U'SE- 'fS.

SCALE.

Specification of Letters Patent.

Patented Dec. 27, 1921.

Application filed October 18, 1916. Serial No. 126,410.

To all whom it may concern:

Be it known that I, LEONARD T. JoHNsoN, a citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Scales, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention is an improved automatic weighing scale, having a novel arrangement and construction of thermostat and operating means therefor, and is a divisional so far as subject matter is common of my prior application, Serial No. 79,314, filed February 19, 1916, for scales, illustrating certain of the features of the present application.

in the class of automatic weighing scales, particularly computing and price indicating scales of the platform type, it is necessary to provide some device which will tend to oorr ct temperature changes in the weighing mechanism. Heretofore it has been customary to interpose a thermostat device be tween the weighing springs and the platform receiving the goods to be weighed, which would act in some manner to tend to equalize the weighing action during extremes of heat and cold. My present invention of thermostat acts in a double capacity, and furthermore the thermostat is rrned of a single substance, the lengthenand shortening of such single substance icing capable of estimation to an exact de- 'ce, and automatically compensating for -e temperature changes. Furthermore, I ilize novel forms of connection for the -ostat and the price computing chart, lerably i terposing the thermostat and as connections with the chart mechanism onl instead of between the weighing 7 springs and weight receiving platform. This construction enables me to utilize a very light, sensitive, and yet strong construction,

it being only necessary to vary the actuating devices of the price chart to compensate for temperature changes in the weighing spring and thereby eliminating the prior method of having heavy, strong thermostatic devices capable of withstanding the strain imposed between the weighing springs and the load.

A still further feature of my present invention consists in the novel connections between the thermostat and the price chart consisting in a leverage construction preferably of the bell-crank type, which will be automatically actuated by the thermostat to increase or decrease the length of the weigh- 111g lever or evening bar, simultaneously correcting the length of the connecting mechanism from the said lever to the price chart. I prefer to utilize a bell-crank lever and to have same operated by the thermostat, whereby said lever will control the length of the effective leverage from the evening bar to the price scale mechanism, swinging it inwardly and outwardly to compensate for capacity while simultaneously moving the price chart connections to keep the same at zero during temperature changes. In other words, one of 'ghing levers which operates the price chart mechanism is lengthened or shortened to maintain the length of paid lever adjusted to correct the weighing'capacity of the scale during temperature changes and also the connections therefrom to the price chart, are automatic lly compensate to maintain the price l chart at zero during all temperature changes.

I therefore am ena led to automaticall correct the weighin and price indicating mechanism. by a si -e. -eo s adjustment of two bars or conne ons and preferably o application of these compensating devices to the price chart mechanism only without disturbing the strong and heavy links or other connecti ns between the weighing novices and the load being weighed.

lVhile the ther J es of my invention in y be aspired to any t pe of price ting or platform scale. I prefer to .AQ same in the rel :orm 0": scale unication ierein a counterpoise is eliminated and an evener bar, in combination with a nain lever, and both operating on the No. l principle, together with a free or floating fulcrum for the eve'ner bar, are made use of.

Other details of the invention, advantageous features and modifications will be hereinafter more fully pointed out and claimed.

Referring to the dawings illustrating a preferred embodiment of the invention,

Figure 1 is a side View, partly in cross section, of my improved type of platform scale embodying a preferred form of the thermostat and connections;

Fig. 2 is a detail view of a modified form of the thermostat and its connections; and

of the pedestals; I prefer Fig. 3 is a still further modified form, shown partly in cross section.

As the present application is a divisional of the said prior application, reference thereto is made for details of the scale construction, the drawings attached hereto illustrating fully the novel thermostat and connections which I have elected to claim in this application.

Referring to the drawings, a base 1 carries a 'vertical support or standard 2, having cylinder 3 supported at its upper portion, and carrying druni e on which the price chart appears, said druni being supported on axles held in suitable bearings at the ends of the cylinder, the end of an axle 5 shown extending through an arbor 6 which also supports said axles and su por ed by the cylinder 3. A sight openi 7 is provided in the cylinder to permit ew of the figures containeduoon the price chart or drum 4:. Rotation of the drum l actuator in connection with the weighing of a load, will indicate the price automatically and in a well-known manner.

7 The weighing platform 8 which is preferably of glass held within a flanged rim 9 en the supporting frame 10, rests upon bosses 11, 11 11 carried on the supportingfranie 10,- said frame'having two central depentwing lugs or side portions 12, constituting bearings resting upon hearing pins 13, carried in opposite forks of the main lever T n ain lever is supported upon pedestals 15 secured to the base 1, bearing pins 17 extending from the main lever 14 and resting in the bearings at the top to arrange the fulcrum for the main lever orwardly of the platform bearings 13, and arrange my second lever, or evening bar20, in a plane parallel with that of the main lever M and 7 connected therewith at the outer ent, by

link 21, fitting over the upper bearing pin 22 held in a projecting h1g2 on the main lever 14 and the lower bearin oin 24 carried in a similarly projecting lug 25011 the evening bar 20. The pivotal bear ngs for the main lever 14 are preferably on line eouldistant between the platform bearings 12,

13, and the bearing of the link 21'. The evening bar 20 is connected to the weighing springsof the scale at the opposite end to that of the link connection and has an inter- 7 mediate flexible or floating fulcrum, consisting in a portion carry ng bearing pins 26 bearing upwardly against acpair of stirrup blocks 28 at each side, each of said blocks being pivotally connected to the platform 1, preferably through staples 29; Theforward end of the evening bar 20 1s forked, hav1ng arms 30 on which bearingpins 32" are car ried. These pins rest upon cooperating bearTv ing blocks 34F held in aforlr 36 connected to the rod 37 3 extending vertically through the r hollow standard 2, and with its upper end flexibly connected onto the crossbar 38, said crossbar in turn having its ends pivotally united to linlrs 89 attached to the weighing spz i s 40, suppo ted each end of the cylinder 3 and from its top by bolts ll and nuts 4 I preferto inake the connections at opposite ends the rod 37 as right and left-- ianded screws, so that rotating the rod 37 will secure an initial springs on the'lever 20. Further adjustment can be obtained b tightening or loosening the nuts o the bolts ll of the weighing springs. tie construction thus descril ed, it will be appreciated that the depression of the hing platform 8 acting through the main lever 14 on the link 21 and thesecond or evening bar 20, will rocl: the on its fulcruin, depressing the forked 30 and pulling downwardly upon the rod 38, linlrs 39,and springs 40 u til can lldlll is reached through the tension the spr igs The levers l and 20 preferabl in substantial parallelism, and'it will be 'ated that by havin the i ranged to rock in ad ustment of the 1, lever 1%, and on t at 6, that it is, in effect direct weighle principle, thes- 2O actin n evening bar in n or the rocko such rock- 1 Q l, l B in Y\81;ili11g s i olllS COHStlllC- c ii prior appli cation. in of two po1nt support '1' llustrated in the drawings, it hold the platform working of rearvra a device to x to horizont- 0 this end ll extend e ne 0 a 1 l 2,"pass1ng l L 11- w 7 5t COUHLSL 530163,

1 during the This'bolt 5G is adjustable vertically, having threadec thereon, above and below the V bro/ch. nuts The link e 8, be-

and 4-9, is-app its ni'vot POllleS 4 7 l a cent al fulcrurn'and the platupport, and he bolt 50 is adjusted L8 is substantially parallel with This construction permits the e held horizontalduring the vertical niovernent imparted theretoin the Gly equ l to the-distance on the inain lever operation of the scale, the entire platform and portions 43 and 48 moving vertically in unison, the lengthenin and shortening of the bar 48 being identical with the same movement of the lever 1 L during such vertical reciprocation. I may apply a dashpot, if deemed desirable, conveniently attaching same by a bracket 53 extending from 46 and being connected with the piston rod 5e attached to a piston (not shown) within the dashpot 55.

To take care, automatically, of temperature changes in the weighing mechanism, I provide a novel form 01" thermostat and preferably connect said thermostat only with the chart actuating devices, as illustrated, although it is equally feasible to utilize a connection with the thermostat to both the spring and chart mechanism, if desires, and in any similar type of scale, either with or without a counterpoise. As the action of the evening bar with the main lever 14 automatically takes care of a counterbalancing and weighing movement impartec to said lever I prefer to apply my in rmostat directly to the evening bar. To this end lie evening bar 20 is formed with depending lugs 58 and 57. The lug 56 at its forward end is threaded to receive the correspondingly thr aded end of the thermostat 58, and the lug 57 is bored to permit the thermostat 58 to extend freely there through. I prefer to make said thermostat of: a single metallic substance, such, for example, as brass, zinc, or ebenoid, to which temperature changes will impart different movement, than that given to the ha r 20, which is, for example, 01" iron. in cold weather the s rings, being of steel, tend to shorten and stiffen, and therefore not only raise the scale bars out of adjustment, but also cause the scale to weigh incorrectly,and in warm weather the tendency is to lengthen and loosen correspondingly. he thermostat 58 is arranged to offset this effect of hot "old tenuierature by the diiierent ring and shortening oithe thern1o- 58 and its connections. At the end of the evening bar 20 is mounted short lever 60, having its atm rod 58, so that variations in the t are efiects on the evening bar 20 8 will tend to rock the lever 60 on its be 20 at 58. I prefer to form the lever 60 as hell crank with its upper end pivoted s bar has, on h end, a sliding block and in each block the end 01"- a rack bar a L secured, which rack bars extend upwardly and mesh with pinions 68 on the outer ends of the axle 5, supporting the price chart and drum l. Oscillation of the lever 60 and vertical movement of the rod 83 therefore produce changed actuation of the price chart relatively with the weighing mechanism, such change being dependent upon the variations of the bar 20 and the thermostat 58 with the temperature and the movement of the bell crank 60. The various threaded adjustments, both of the thermostat in the lugs 57 and the rod 63 in the block 6%, permit of quick and ready assembling to secure appropriate working of the thermostat mechanism.

In Fig. 2 I have illustrated a modification of the connection from the thermostat 58 to the rod 63 and also a construction uniting the rod 37 to the weighing springs and the evening bar 20 controlled by the thermostat to increase or decrease the effective leverage of the bar 20 and compensate for temperature changes. This construction is of advantage in certain types of scales. The "forward end of the evening 20 is recessed at 70 and at 71. and a yoke 72 having one end 73 threaded onto the end of the thermostat 58 is provided with an upper portion 7 adapted to slide within the recess '70 and project out from the evening har carryinga bearing point 75 on which the block 3-1 carried by the rod 37 contacts. This enables the action of the thermostat control the leverage between the evening ha 20 and the 'ghing springs, the recess 70 being of suificien movement. *0

The lower part 76 of the yoke projects t rough the recess 71 and is pivotally connected at 77 to the bellcranlr 60 which operates the price chart actuating rod 68, as has been described, said lever be-- ing pivoted at 78 on a bracket 79 secured to the "front of the evening bar. It may be desired to brace the yoke 72 by cross piece 80, for which a correspondingly enlarged recess 81 will be formed to permit the relative movement of the yoke and the evening bar 20. In this construction both the weighing mechanism and the price chart mechanism are corrected by the thermostat maintaining the weighing .lianism 1 proper condition for uniformity of weighingca-pacity, while the bellcranl: lever acts to move the price chart lever 68 downwardly and upwardly to hold the drum and chart scale at zero.

In Fig. 3 I have illustrated a still further modification showing a construction whereby the connection between the evening bar 20 and rod 37 is controlled by the thermostat 58 and proportioned to the action of the hermostat on the bellcrank 60 and price chart actuating rod 63. In this construction tie r cess 70 receives a slide 82 having a bearing 83 to connect it with the rod. 37.

t length to permit the desired sliding J Thethermostat 58 carries a yoke 8% having one arm 85 pivoted'to the bellcrank 60 and a short arm 86 pivoted to a lever 87, said lever being arranged in a recess 88 in the evening.

bar 20. This lever is pinned to the bar 20 at 89 and has a slot 90 in its upper portion engaging a pin 91 on the slide 92. Relative movement between the thermostat 58 and eveningbar 20 will act to throw the'slide 82 and a greater distance than the said relative movement, which distance maybe pro- )ortioned in an desired de ree. The wei 'hy z: e

lllg correction afforded by tiis construction is capableor"; a considerable range of adjustment, depending upon the location of the pin 91 and the pivot 92 connecting the arm 86 with the lever 87, aswill be readily appreciated. The construction also aiiords great strength between the weighing s irings and the load to be weighed, while permittin a simple and ligiit thermostat 58 to be einployed. r

The operation will be readily understood from the foregoing description and theaccuracy and efiiciency of the thermostat corrections will be appreciated by those skilled in this art. I believe that the provision of a thermostat acting upon either the price chart mechanism'or the weighing mechanism 'to effect correction, or temperature changes, s novel, and also that the PIOVlSlOIl of a thermostat controlling the length of one lever ing or flexible fulcrum and the various other novelfeatures of my improved scale, as I have elected to claim these features in my said prior application.

' My invention is further described and d' fined in the form of claims as follows:

7 l. Ina scale or" the k nd described, the

combination oi a price chart, a weighing lever, means to control the movement of said lever with an evening bar movable with said lever parallel therewith andinterposed between said lever and said means, a thermostat parallel with said lever and evening bar, and connections from said thermostat to theprice chart to compensate for temperature changes;

2. In a scale of the kind described, the combination of counterbalancing weighing mechanism, a weighing lever and means to control the movement of said lever with an evening bar interposed between said lever and said means, and a, thermostat carried by said evening bar and operable to automatically compensate for temperature changes in the scale mechanism.

3; A scale of the class described, having weighing mechanism including a. main wei hing lever and an evening bar parallel therewith and connected thereto, a price chart, a thermostat having one end afiixed to said evening bar, and means carriedby the evening bar arranged to be actuated by the free end oi said thermostat connected to the price chart to compensate automatically for temperature changes in the weighing mechanism. r

' l. A platform scale or" the class described, having a vertically reciprocating platform, means to hold said platform in a horizontal plane during it movements, a price chart,

.wei 'hin mechanism for'said alattorm. in-

eluding a main lever pivoted forwardly of the platform support thereon, a second lever parallel therewith, connected to said main lever, and a thermostat movable with the second lever and connected to said price.

chart to actuate the price chart through the differences imparted to the second lever and said thermostat by temperature changes, tocompensate in the indications of the price chart only for temperature changes in the weighing mechanism.

5. In a scale of the class described, zontal weighing lever carrying a thermostat, a bellcrank pivoted to said lever and coir nected with the thermostat and having its other end connected with the price indica ting mechanism, whereby I the thermostat will a-lioricontrol thehorizontal length of thelever to compensate for temperature changes in the capacity of the weighing mechanism and will controlthe vertical length of said price computing mechanism to maintain the indicator at Zero.

In testimony whereof I have signed my name to this specification in the presence of two'subscribing witnesses. V i

C LQONARD T. JOHNSON.

Witnesses: J r

JAMES R. Honnnn,

HAROLD J CLARK. V 

